1. Field of the Invention
The present invention relates to the field of printing, and more particularly to the use of curved multi-jet print heads to print upon laterally curved slats prior to their assembly into louvred structures such as Venetian blinds.
2. Description of the Related Art
From typewriters to laser operated graphics printers, the printing field is ripe with printing devices. Despite the tremendous breadth of potential surfaces to be printed upon, engineers have designed a correspondingly broad selection of printers for many of these jobs. In addition to the usual paper jobs, equipment for printing, engraving, stamping, and the like has been developed for vinyl signs, CD-ROMs, plastics, metals, and many other materials. Airplane skywriting fills an unusual need to place text in the sky, further attesting to mankind's ingenuity in printing just about anywhere.
Engineers still encounter some substantial challenges, however, when seeking to print upon certain types of surfaces. One difficult surface is the narrow, curved surface of a Venetian blind slat. It may be desirable to apply printing to Venetian blind slats, for example, to spruce-up normally bland Venetian blind slats by covering the slats with a nature scene, wood grain, photograph, etc.
One conventional approach employs a screen printing technique to print directly onto flat Venetian blind slats. After this, the slats are bent into the desired curvature. Although this approach is desirable for its ease of printing, the bending of the Venetian blind slats may damage or distort the overall image. For example, bending the slat may crack the slat or the printing material thereon. Another approach prints upon flat paper with adhesive backing, divides the paper into strips of suitable dimensions, and then adheres the strips onto Venetian blind slats. As with the previous approach, this process may also cause some distortion to the image, since its flat printing does not account for the ultimately curved shape of the image. Additionally, this approach may also be costly because sufficient adhesive paper is required to completely cover the Venetian blind slats, or else risk an unsightly division between the adhesive paper and the uncovered regions of the slats. Even with adhesive paper that matches the color of the Venetian blinds, the two materials may ultimately take on different appearances due to diverging wear, dust resistance, dirt accumulation, etc.
In contrast to the foregoing methods, another technique uses silk screening to apply the desired image directly onto the blind slats. Silk screening ink is typically flexible, and therefore resists cracking due to flexure. Nonetheless, problems have been encountered with silk screening, too. During silk screening, the screen must be kept taut. As a result, the ink does not flow evenly over the curved surface of the slats, and may even run. Moreover, this procedure is time consuming and expensive because it requires a different individual screen for each slat. Costs can be saved by applying the same image to some or all of the slats in suitable applications, e.g., where the original image contains non-distinct elements, such as ornamental patterns, leaves, wood grain, etc. Another problem with silk screening is that an entirely new set of screens must be created to lay down an image on Venetian blinds with different dimensions.
Consequently, known techniques for printing upon Venetian blinds with curved slats are not completely adequate for some applications due to certain unsolved problems.